Robert
As it appears you are starting to re-factor osgTerrain I have a few
suggestions.
1) DataSet is something of a behemoth (approx 5000 lines) and would
benefit from being broken down into standalone classes (and files). It
already lends itself to that as there are a number of classes.
2) My recent submission on osgTerrain building in specific support for
vector data sets should be considered. I should be stronger and say that
height data by default should be considered as vector rather than
raster. The majority of height data from various agencies around the
World are vector data sets.
GDAL incorporates vector data via OGR (I think) but the formats are
fairly limited.
3) With the use of vector data an expansion of HeightField might be
useful. I derived a class from HeightField which allows better
definition of the normals at the edge of tiles (you need to expand the
field somehow to get the next point off the tile). I also added direct
Node generation into the class rather than use the Shape / Drawable method.
4) I have a problem with my derived version of osgTerrain in that it
crashes on my largest test case (20km x 20km at 0.5m resolution aerial
photo). It used to crash on smaller cases, but adding tests where, for
example, new Geodes fail to be created, appeared to cure those. So it
may be a memory problem. It also fails at a different point each time
(usually about 30% of the way through) which is after about 30 minutes.
I have to sort this but it leads to a useful suggestion.
The set up of the database does not take long (about 5% of the total
time). It would make sense to create a file containing the
DestinationTile information at that point. Couple this with updating
(and flushing) the archive index after every file write means that, by
comparing the DestinationFile structure with the files already in the
database, it would be feasible to re-start a database creation from the
point where it failed.
It also allows repair of a database with re-generating the whole thing.
--
Regards
Alan Harris
ReSoft Ltd
Cornwallis, Burycroft Road
Hook Norton
Banbury, OX15 5PR, UK
Tel: +44 (0) 1608 730707
Email: [EMAIL PROTECTED]
Web: www.resoft.co.uk
_______________________________________________
osg-users mailing list
[email protected]
http://openscenegraph.net/mailman/listinfo/osg-users
http://www.openscenegraph.org/
